Occurrence, Composition and Formation of Ruppia, Widgeon Grass,
balls in Saskatchewan Lakes
RANDY W. OLSON1, JOSEF K. SCHMUTZ2,3, and U. THEODORE HAMMER4
1W.
P. Fraser Herbarium, University of Saskatchewan, 51 Campus Drive, Saskatoon, Saskatchewan S7N 5A8 Canada
for Studies in Agriculture, Law and Environment, University of Saskatchewan, 51 Campus Drive, Saskatoon,
Saskatchewan S7N 5A8 Canada
3Corresponding author Schmutz. [email protected]
4 Department of Biology, University of Saskatchewan, 112 Science Place, Saskatoon, Saskatchewan S7N 5E2 Canada
2Centre
Olson, Randy W., Josef K. Schmutz, and U. Theodore Hammer. 2005. Occurrence, composition and formation of Ruppia,
Widgeon Grass, balls in Saskatchewan Lakes. Canadian Field-Naturalist 119(1): 114-117.
Widgeon Grass (Ruppia maritima) is an aquatic vascular plant (Ruppiaceae) which has been the source for rare balls of plant
material found at the shores of lakes on four continents. In North America, the lakes involved were in North Dakota, Oregon,
and now northern and southern Saskatchewan. The formation of the balls has not been observed in nature, but similar balls
have been produced in other studies with Posidonia or Turtle Grass (Hydrocharitaceae) fibers under the wavelike action in a
washing machine. Our samples are from a saline lake in southern Saskatchewan (49oN), and an over 40-year-old sample from
an unknown lake north of the boreal transition zone (52oN). Comparisons of the plant material with herbarium specimens
confirm that the balls are almost entirely comprised of Ruppia maritima, with minor items including invertebrate animal parts,
sand pebbles and feathers. The context in which the material was found is consistent with the proposition that they are formed
by Ruppia inflorescences breaking apart, drifting to near shore due to wind and being rolled into balls by wave action.
Key Words: Ruppia maritima, Widgeon Grass, plant balls, saline lake, Saskatchewan.
Unusual balls of plant material were encountered at
shores of two different lakes in northern and southern
Saskatchewan. Judging from available literature, similar
balls have been found in Europe, North America and
New Zealand (Cannon 1979; Essig 1948; Gerbeaux and
Ward 1986). While the actual formation of these balls
has not been observed in nature, the combined action
of waves on fragments of aquatic vegetation near shores is
thought to be involved. Such balls have, however, been
produced using Posidonia or Turtle Grass (Hydrocharitaceae) fibers under the wave-like actions simulated by a washing machine (Cannon 1979).
Names for the plant balls exist in Dutch, English,
French, German and Italian, 15 names in total (McAtee
1925). Some of these names date back to classical times
(E. A. Parry in Cannon 1979). This attests to a widespread, even if rare, occurrence of these balls. The
names also attest to a degree of fascination; a curiosity
likely enhanced by the unpredictable occurrence of
these structures in nature.
Sample Sources
Our collection includes six balls of plant material in
two sets. One set was located at Sandoff Lake (49°00'N,
104°18'W) in the Lake Alma Upland within the Missouri Coteau of south-central Saskatchewan. Sandoff
2
Lake is a 1 km saline lake in a hill-and-dale landscape.
Sandoff Lake has no above-ground outflow, and lies in
the Missouri-Mississippi River drainage (Fung et al.
1999). As is typical of many saline lakes, it is probably
fed through ground water in addition to runoff and
springs visible on the lake’s shore. Sandoff Lake goes
dry in some or most years. On 20 October 2000 there
was no standing water covering the white salt flat.
A second set of plant balls was found during lake
studies in the 1950s by D. S. Rawson (e.g., Rawson and
Moore 1944). The balls were given to UTH about
1960, but data on time and location of collection were
not recorded. The collection has been given to Glenn
Sutter, for inclusion in the natural history collections
of the Royal Saskatchewan Museum in Regina (RSM
Accession 17443).
Results and Discussion
More than 50 plant balls were first found on 6
July 2001 by JKS along the southeastern shore of
Sandoff Lake (Figure 1) where the prevailing winds
are northwesterly. The balls were scattered in a band
approximately 3 m wide and 100 m long, at the high
water mark where the pebbly shore merges with shortgrass prairie. The balls were still present, although more
encrusted in salt, on 30 June 2003. Their position in a
single layer, similarity in salt or algal coverage and
slightly compressed form suggests that only one generation of such balls occurred during the three years. Their
position at the upper reaches of the shore suggests that
the balls may have been washed there during strong
winds but not returned to the lake with the receding
water during calmer weather. A walk around the lake revealed two sets of balls on the east but none on the west
(primarily upwind) shore.
Analysis of the material in the two sets of balls
showed that they were composed mainly (greater than
95%) of Ruppia inflorescence stems, peduncles, and
114
2005
OLSON, SCHMUTZ, AND HAMMER: RUPPIA BALLS IN SASKATCHEWAN
fruits. The fruits were black, ca. 2 mm long, and beaked.
These identifications were based on comparisons between the samples and specimens from the W. P. Fraser
Herbarium, and descriptions from several floras (e.g.,
Haynes 2000). In three of the balls from Sandoff Lake,
Ruppia maritima L. was identifiable. Small amounts of
other material found included twigs, small pebbles, and
a feather.
Saskatchewan has two species of Ruppia: R. cirrhosa
(Petagna) Grande (synonym = R. occidentalis S. Wat.)
and R. maritima L. (Harms 2003). Ruppia maritima is
found in the southern third of Saskatchewan, and Ruppia cirrhosa is found in the southern half of the province
(Hammer and Heseltine 1988; W. P. Fraser Herbarium).
In North America, Ruppia maritima is found throughout
eastern and western coastal regions (Haynes 2000).
Ruppia cirrhosa is found from Alaska south to Texas
and From California east to the Great Lakes (Haynes
2000).
The two species of Ruppia belong to Ruppiaceae, the
Ditch-grass family, also known as Widgeon Grass
(Haynes 2000), The one genus includes approximately
10 species worldwide, and two in North America. Ruppia is an annual, or rarely perennial, sessile herb submersed in brackish or saline water. Flowering occurs
spring-fall.
The plant balls as shown by Essig (1948), and
Swanson and Springer (1972) are highly similar to our
material. Also, R. maritima L. seems to be the primary
plant species involved, at least in North America (Table
1). This suggests that the conditions that favour ball formation are relatively specific. The involvement of saline
115
FIGURE 1. Ruppia maritima balls located at the southwest
shore of Sandoff Lake in Saskatchewan, on 6 July
2001.
FIGURE 2. Two Ruppia maritima balls. One (left, 6.0 cm diametre) from Sandoff Lake, and
the larger (right, 13.5 cm) from northern Saskatchewan.
THE CANADIAN FIELD-NATURALIST
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Vol. 119
TABLE 1. Characteristics of plant balls as reported in the literature and found in our Saskatchewan samples.
Site Name
Location
Lake Type
Plant Species
Reference
No name
Mediteranean
No name
Miller Lake
Little Borax Lake
Sandoff Lake
Unknown
NE North Dakota
–
Near Dawson, ND
Oregon
California
S Saskatchewan
N Saskatchewan
Saline
Sea shore
Saline
–
Saline
Saline
Unknown
Ruppia maritima
Posidonia oceanica
Ruppia maritima
“similar” to FPM
Ruppia maritima
Ruppia maritima
Ruppia maritima
SS 1972
JFMC 1979
FPM
GWF
EOE 1948
This report
This report
References: SS = Swanson and Springer 1972, JFMC = Cannon 1979, FPM = F.P. Metcalf in McAtee 1925, GWF = G. W.
Field in McAtee 1925, EOE = E.O. Essig 1948.
lakes may not be crucial to ball formation but merely
reflect that Ruppia is a saltwater species. The stems of
Ruppia are delicate, relying on the surrounding water
to support their mass (Kantrud 1991*). The stems are
likely susceptible to breakage during periods of unusual
turbulence. The stem bases also decay as the plants
reach senescence (Kantrud 1991*). These two factors
would leave large amounts of plant material in the water
in late summer and/or fall, likely leading to the homogeneous content of the Ruppia balls.
Given the structure of the balls, the location in which
they were found and explanations from the literature,
we suggest that the following mechanisms are involved
in their formation. The fibrous stalks of Ruppia are
prone to breakage and to sticking together. Two balls
that were cut (Figure 2) and one that was teased apart
suggest that the material is Ruppia throughout and does
not contain any other material in its core. When the
stems of the Ruppia break and tangle together, floating
mats accumulate and are driven by wind to the shore
(e.g., Essig 1948). Here, the repeated wave action in
combination with the resistance provided by the shore
in shallow water rolls the mat back and forth. This
rolling action was thought responsible for producing
balls of plant material in the lint trap of a washing
machine (Cannon 1979). Finally, on windy days the
balls may be washed up onto shore out of reach of the
lapping waves on calm days that might otherwise return
the balls to water where they may decay. The distribution of balls at Borax Lake (Essig 1948) suggests that
the balls were deposited over time as water evaporated
and the shallow lake receded, differing slightly from our
accumulation at the shore. Judging from the misaligned
fibers in our material, interconnected in seemingly all
directions (Figure 2), we doubt that the balls have
grown in layers (e.g., Essig 1948). Instead, the different
sized balls may simply be due to different amounts of
plant material in a mat that starts to roll on the shore. In
the Sandoff Lake sample, salt spray had encrusted the
balls and, combined with grass shoots growing through
the balls, had firmly anchored the balls on the upper
shore. The Sandoff Lake balls tended to be oval. We
suggest that they were round originally but that the
material settled to an oval shape after they were covered
in salt, dried and became anchored on the shore.
The formation of balls by wave/wind action and
friction is not limited to aquatic plants. Near Blaine
Lake, Saskatchewan, wind combined with large and
wet snowflakes led to snowball formation observed
on the packed snow in a yard (Julie Hupé, personal
communication). Pierce et al. (2004) compared amorphous, decomposed remains of large animals that
washed up on a Chilean shore in 2003 (Chilean Blob),
with other such “carcasses” variously reported as sea
monsters for over a century. Such sightings occurred in
Bermuda (n = 2), West Coast of Tasmania, and
Northeast Coast of the United States in addition to
Chile. The authors identified the material as decomposed remains of large whales. The material was held
together by cross-hatched layers of collagen fibers.
This flexible layering of collagen in a blob was different from the firm arrangement of the inflorescence
stems in our Ruppia balls.
Acknowledgments
Dennis Dyck kindly took the photo of the balls and
Blaine Novakowski sliced them for analysis. Glenn
Sutter cataloged the material as part of the Royal Saskatchewan Museum’s collections (RSM Accession
17443).
Documents Cited (marked * in text)
Kantrud, H. A. 1991. Wigeongrass (Ruppia maritima L.):
A literature review. U.S. Fish and Wildlife Service, Fish
and Wildlife Research 10. Jamestown, North Dakota:
Northern Prairie Wildlife Research Center Home Page.
http://www.npwrc.usgs.gov/resource/literatr/ruppia/rup
pia.htm (Version 16JUL97).
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Essig, E. O. 1948. The Ruppia balls of Little Borax Lake.
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Received 23 April 2004
Accepted 11 February 2005